As quantitative data from a wide variety of techniques and levels of investigation become available for a particular nervous system function, it is both possible and advisable to attempt to assimilate such information into a comprehensive model of the underlying mechanisms and their interactions. This project consists of the development of such models and the necessary analytical and mathematical techniques for their implementation and testing in several areas of intensive experimental investigation by LNLC members and the scientific community at large. Several lines of evidence from walking cats suggest that primary afferents are depolarized at certain moments during stepping, and that this controls the strength of the afferent signals. A model of the motoneuron with after hyperpolarization approximates the response of real motoneurons to varying injected currents. By extending factor analysis we have found the optimum mixture of input signals from color receptors that would be used by ganglion cells of the retina using the criterion that the signals they generate should be independent signals. We have derived a relationship between the firing of synaptic terminals onto a neuron and the rate of information flow into the neuron, when the terminals fire irregularly and the neuron is affected by other terminals at the same time. We have the first evidence that an important feature of the shape of a neuron is its fractal dimension.